1. Field of the Invention
This invention pertains to the general field of timers and controllers to regulate the usage of electrical appliances and equipment. In particular, it provides a new device to limit the amount of service time allowed for the use of a telephone.
2. Description of the Prior Art
The idea of affecting the availability of power to electrical appliances and other equipment in order to control their use has been implemented in a variety of ways by mechanical and electrical means. A common feature of these devices is the presence of a power control switch that is accessible only through a lock or other protective hardware.
For example, U.S. Pat. No. 3,581,029 to Noiles (1971) describes a television control for regulating the cumulative viewing time. The device features an internal outlet for receiving and securing the television's plug and an external plug for connection to any power source. A predetermined total length of time is made available to the viewer, who controls the utilization of that time with an on/off switch on the exterior of the device. An internal mechanical accumulator keeps track of the time used and switches off the unit when the total allowed time has expired. The instrument also resets itself every 24 hours.
U.S. Pat. No. 3,833,779 to Leone (1974) shows another television timer, which provides essentially the same function of the invention described by Noiles, but without the accumulator and the automatic resetting features. Like that invention, this apparatus can be used with any appliance requiring electrical power and is not limited to television sets.
In U.S. Pat. No. 3,879,332 (1975), Leone teaches another use of his prior invention in an application specific to television sets. The device is incorporated into the set to control the TV circuitry directly, rather than the power to it, so that the television remains plugged in the normal power outlet. As previously done in the art, the mechanism can also be combined with a coin slot to permit the purchase of viewing time.
U.S. Pat. No. 3,925,629 to Albinger (1975) illustrates a time switch for controlling the delivery of power from an electrical outlet according to a predetermined on/off schedule. The device has two automatic modes permitting a choice between repeating the same schedule every day and periodically alternating between different ones. It also allows manual control as a regular switch.
The invention is designed for use with any appliance requiring electrical power from a regular outlet, such as lamps and radios, but its control is not secured and is accessible to anyone.
In U.S. Pat. No. 3,997,742 (1976), Marquis describes another automatic timer switch wherein the switching mechanism is simplified and the number of parts involved is reduced. This patent is basically the same as Albinger's in function and purpose, and it very specifically shows an alternative mechanism to achieve the same result. Some minor features differentiate the two, such as the presence of a dual outlet instead of a single one, but the operational characteristics of the two are essentially the same.
U.S. Pat. No. 4,297,546 to Koch (1981) discloses yet another type of timing switch, wherein different mechanical parts are employed to achieve the same results. As the inventions of Marquis and Albinger, this switch can be operated automatically, in combination with a timing device incorporated into the apparatus, or manually, like a regular electrical switch.
Finally, U.S. Pat. No. 3,508,392 illustrates an invention for recording the length of outgoing telephone calls from a dial-type receiver. The apparatus does not control in any way the duration of the calls, either individually or cumulatively.
Thus, the prior art does not include an apparatus to control the cumulative time allowed for the use of a telephone. As every parent knows, such a product would be very desirable in order to limit the time spent by children on the phone, especially in view of the now common practice of allowing each child a private phone connected to the household telephone line. This kind of device would be similarly useful to control phone usage by house keepers, and employees in comparable business environments. Therefore, a need exists for an inexpensive and practical device for controlling the total amount of time allowed for telephone usage.